In general, the atomizer serves as an energy conversion mechanism to convert a volume of the liquid (such as the fuel) into a multiplicity of small droplets and then ejects these droplets so as to produce a high ratio of surface to mass in the liquid phase and thereby achieve high rates of mixing and evaporation. The atomizer may be used in applying agricultural chemicals to crops, paint spraying, spray drying of wet solid, food processing, cooling of nuclear cores, gas-liquid mass transfer applications, dispersing liquid fuels for combustion, and many other applications. As shown in FIGS. 1 and 2, the cross sectional view of a prior art atomizer and a nozzle which is installed with a nozzle cap are illustrated, respectively. The atomizer includes a seat 10, an oil supplying tube 12, a fuel supplying flow channel 12, an embedding rod 13 and a nozzle cap 14. As fuel flows to the fuel supplying chamber 15 from the fuel supplying tube 12, by the combination of the fuel supplying flow channel 11 and the seat 10, the fuel will pass through fuel supplying chamber 15, and then enters into the fuel supplying strip formed by the nozzle cap 14 and the embedding rod 13. The inner side of the nozzle cap is a hollow chamber. The vortex flow channels are constructed by the embedding rod 13 and the nozzle cap 14 from the vortex chamber 16. The fuel is accelerated through the vortex flow channel and then is ejected from a release orifice in order to attain the effect of atomization. The defect is that the seat 10 used in the pivotal axis atomizer is very complex (referring to FIG. 1), thus the finishing and assembling work are difficult. Moreover, the gaps after assembled is increased, thus the atomization effect is reduced.
Therefore, based on the principle of fluid dynamics, the object of the present invention is to design an atomizer which is suitable to be used in all kinds of industrial environments. Under different kinds of working fluid, there are some factors which will affect the performance of a pressure-swirl atomizer, which are:
1. Flow number (FN) PA1 2. Differential pressure (.DELTA.P) PA1 3. Mass flow of the working fluid (dm/dt) PA1 4. Pressure loss induced by the friction of flow channel. PA1 1. Low differential pressure, below 7 kg/cm.sup.2 (0.686 MPa). PA1 2. High mass flow ratio. PA1 3. High flow number FN=2.4.times.10-6. PA1 4. Simple flow channel structure with fewer components, which may be easily finished and assembled PA1 5. Reducing SMD value to less than 40 .mu.m
Reducing Flow number, increasing differential pressure, reducing mass flow and pressure loss induced by the friction of flow channel are beneficial to the SMD (Sauter mean diameter). Since in various bad industrial working environment, such as small installation space (FN large), fewer number of nozzles (large mass flow ratio), lower differential pressure, etc. Thus, it is eagerly demanded to have a brand new design which can further reduce the SMD value and have the following specifications:
The fuel flow rate m.sub.L and SMD can be expressed by EQU m.sub.L =CdA.sub.0 (2.beta..sub.L P).sup.0.5 (1) EQU SMD=2.25.sigma..sup.0.25.mu..sub.L.sup.0.25 m.sub.L.sup.0.25.DELTA.P.sub.L.sup.-0.5.rho..sub.A.sup.-0.25 (2)
According to the requirement of the fuel flow rate m.sub.L and SMD value, we can decide the suitable operating pressure P, final orifice area A.sub.0, and discharg coefficient C.sub.d. ##EQU1##
Now, we decide the actual discharge velocity U, d.sub.0, l.sub.0, D.sub.s, and L.sub.s by means of the mounting space to meet the required C.sub.d value.
The actual discharge velocity U can be obtained by velocity coefficient K.sub.V, the ratio of the actual discharge velocity to the theorectical velocity corresponding to the total pressure differential across the nozzle, i.e., ##EQU2##
According to aforementioned requirement, a front plunger simplex atomizer is designed. The present invention has the following advantages: 1. Small installation space and low operation pressure. 2. Simple flow channel structure. 3. Fewer components. 4. Easily assembled without any error. 5. Easily controlling the gap by a central plunger fastening barrel is adapted.